639723283 has 4 divisors (see below), whose sum is σ = 639894528. Its totient is φ = 639552040.

The previous prime is 639723239. The next prime is 639723299. The reversal of 639723283 is 382327936.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 639723283 - 2¹³ = 639715091 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (639723883) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 79891 + ... + 87532.

It is an arithmetic number, because the mean of its divisors is an integer number (159973632).

Almost surely, 2^639723283 is an apocalyptic number.

639723283 is a deficient number, since it is larger than the sum of its proper divisors (171245).

639723283 is a wasteful number, since it uses less digits than its factorization.

639723283 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171244.

The product of its digits is 326592, while the sum is 43.

The square root of 639723283 is about 25292.7515901295. The cubic root of 639723283 is about 861.6496562947.

The spelling of 639723283 in words is "six hundred thirty-nine million, seven hundred twenty-three thousand, two hundred eighty-three".